榉树木材的发育解剖学研究

An Anatomic Study on the Wood Development of Zelkova schneideriana

应用多种制片方法对榉树木材的发育解剖学进行了研究。结果表明:榉树木材为环孔材,年轮明显;早材部分管孔由1～2列导管分子呈环状排列,而晚材部分则由多个螺纹维管管胞和小导管分子组成管孔团,木纤维径向整齐排列,其含量在边材部分较少,而在心材部分较多,这表明榉树在不同生长期形成层分化的各种类型细胞的比例不同;木射线异形多列,由横卧细胞构成主体,而由方形细胞或直立细胞构成射线的边缘部分,形成多列射线的单列尾端;轴向薄壁细胞傍管型环管状。小导管分子和维管管胞具螺纹加厚,导管在心材中为侵填体填充而增加了木材的耐腐性。

With several methods,the developmental anatomy of the wood of Zelkova schneideriana was studied.The results are as follows:The wood of Zelkova schneideriana is ring porous,and its annual ring is very distinct.The pore pattern of the early wood is ring arrangment which is composed of 1～2 rows vessel elements,and the pore pattern of the late wood is pore cluster which is composed of many spiral vascular tracheid and small vessel elements.The fibers are radially arranged.The content of fiber in sap wood is less than that in hearty wood,which indicate that the rate of different tissues differentiated from cambium varies in different growth periods.The wood ray is heterogeneous and multiseriate ray.The main parts are made up of procumbent cells,and the marginal ray cells are squared cells or upright cells that form the end of their uniseries.The axial parenchyma is vasicentric.Vascular tracheid has spiral thickening.Vessels of hearty wood have tyloses,which strengthen the character of corroderesistant and guarantee the fine character of wood of Zelkova schneideriana.The tree grows relative quickly in former 30 years,and its annual ring is 3.57 mm wide in average.After 30 years,the width of annual ring decreases dramatically.Its mean width is 1.17 mm.This result may be closely related to the individual examined tree.